I wonder if the shackle key is their version of the Spyderco Hole, but is being called a shackle key for the sake of legalities and/or marketing? I was unaware Opinel was expanding their line. Like others, this knife is not for me. I like the whistle; I thought it was clever when it was added to the Tool Logic Knives. I do not care for the serrations though or the price. I'd rather purchase a classic no. 8 and a Fox 40 whistle for half the cost of this knife, and even then I'd rather purchase a different tool altogether.